| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical filter in which an electromagnetic wave shielding function is enhanced by suppressing fall of transmissivity. SOLUTION: The optical filter 3 has an optical film 5 formed on a transparent film 4 by laminating film M in the laminating order of an ITO layer 10, a metal (Ag) layer 11, and an ITO layer 10 repeatedly 3-5 times as a repetition unit wherein the sheet resistance of the optical film 5 is 1.5Ω/sq. or less, and the light beam transmissivity is 15% or less in the waveform region of 800-1,200 nm. The optical film 5 is suitably constituted by laminating a laminate film of an ITO layer and an Ag layer having layer thickness of 450 nm and 200 nm repeatedly 4 times, thus obtaining an optical filter 3 having a sheet resistance of 1Ω/sq. or less. Such optical characteristics as the light beam transmissivity is substantially 0% in the waveform region of 800-1,200 nm, and 35% or above in the vicinity of wavelength of 550 nm. COPYRIGHT: (C)2007,JPO&INPIT
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